Just bought a rpi 3a+ which I want run piaware on.
Downloaded the piaware image, moved it to the memory card using etcher as recommended and when I power it on, nothing happens.
It refuses to boot, only the red led light is constantly on and the screen connected to the hdmi only display the rainbow color thing.
Ok so after checking up on this you won’t be able to use the piaware image, it probably is based on a Raspbian version that is too old.
You can use Raspberry Pi OS – Raspberry Pi (stretch lite is recommended) and install the package version.
Or if you have another RPi handy you can update the piaware image on that with
Rainbow screen hang generally indicates a bootloader problem. AFAIK the bootloader/kernel should be fine on a 3A+, but I don’t actually have one on hand to test with.
Does a standard Raspbian Lite image work?
(edit: Hm, ok, the 3A+ is newer than I thought; you’ll probably need to wait for a new piaware sdcard image or use the standard Raspbian image as suggested by wiedehopf)
I used an older Pi to upgrade the image install via apt-get, then put the sd card in the a+. Not sure if that only works with a Pi 3 though, or any pi will do.